1. Field of the Invention
The present invention relates to a method and apparatus for cleaning mail processing equipment, and in particular to a cleaning system for removing accumulated dust and particulate from the mail processing equipment.
Modern mail processing equipment is designed to rapidly receive and sort large quantities of mail. To accomplish this task, various types of mail processing equipment have been employed. Of particular interest to the present invention are optical character readers (OCR) such as OCR Model MLOCR-B, available from Electro Com Automation LP, Arlington, Tex. The OCR includes a conveyor system which rapidly transports the mail past an optical character reader which in turn reads information written on the envelope. This information is then processed by a computer and used to sort the mail.
Also of interest are wide area bar code readers (BCS) such as Model BCS 880, available from Electro Com Automation LP, Arlington, Tex. BCSs are used to read the bar code printed by an OCR on an envelope and to sort to a deeper level, i.e. station and carrier route.
Another type of mail processing machine is an advanced canceler system (AFCS), such as Model AFCS FAM 885, available from Electro Com Automation LP, Arlington, Tex. AFCSs are used to cancel mail arriving at the post office. They sort the mail into the following categories: (1) OCR readable, (2) non-readable, (3) bar code printed on envelope, (4) business reply, and (5) non-cancelable mail.
Still another type of mail processing machine of interest is a delivery bar code sorter (DBCS), such as Model DBCS II 994, available from Electro Com Automation LP, Arlington, Tex. DBCSs are similar to the BCS but have even deeper level of sorting (to carrier walking sequence) and have more sort bins.
Common to such mail processing equipment are conveyor systems used for transporting the mail along at least a portion of the equipment. Usually the conveyor system will include a pair of spaced-apart belts disposed along a series of pulleys so that mail can individually be transported between the belts. As mail travels along the conveyor system, particulate is generated within the equipment which can prevent the equipment from remaining in good working order. This problem is compounded since a large volume of mail is transported by the conveyor system causing rapid accumulation of the particulate.
Present methods for removing the accumulated dust and particulate require the machines to be shut down for a considerable length of time so that the accumulated particulate can be accessed for removal. The particulate is removed by a blow out procedure which is usually required every two hours on a run of sixteen to eighteen hours per day. The blow out is required for each BCS, OCR, AFCS, and DBCS. However, this blow out is rarely performed because of the extensive down time. Such an extensive down time is undesirable for a variety of reasons including labor costs incurred in breaking down and cleaning the equipment and slowing distribution of mail.
It would therefore be desirable to provide a cleaning system for mail processing equipment that could reduce or eliminate the down time required to remove accumulated particulate from the equipment. The system should also be efficient and economical, and be compatible with existing mail processing equipment.
2. Description of the Background Art
U.S. Pat. No. 4,221,329 describes the use of an airstream to create a "fluid curtain" in order to prevent accumulation of particulate on a photo detector.
U.S. Pat. No. 5,245,601 describes the use of ribs on a turntable to generate air flow to blow dust away from optical equipment.
U.S. Pat. No. 4,441,018 describes an apparatus using temperature differences in air to create air flow to remove particulate from photoelectric components of the apparatus.
U.S. Pat. Nos. 5,097,563, 4,603,898, and 4,678,224 describes systems for blowing air over windshields to prevent particulate accumulation on the windshields.
U.S. Pat. No. 3,469,088 describes the use of a pressurized cleaning fluid for cleaning the lens of a vehicle running light without interrupting the operation of the vehicle.
U.S. Pat. No. 4,187,868 describes the method for cleaning the surface of an optical element by applying a liquid to the surface and causing the liquid to vibrate.